Once you get through the conversation w/Juhani about how her family fared on Taris and how she made it to Dantooine the path should be clear to encounter Xor (Kashyyyk, Manaan, Korriban). After you have your initial confrontation to have to go somewhere on that planet where you can warp back to the Ebon Hawk in order to confront Xor and close out that side quest. At least that's the only way I've ever gotten it to work for me.

@qui-gon--interesting, never had that problem w/Xor & Ziagrom quests.

I talked about all with Juhani and found all maps/ all except Manaan (two saves, both with all talked) and never met Xor.